Cabinet plug

I am a high school science teacher and some of the cabinet locks in our lab classrooms are missing locks. This is a plug that fits in that hole in the drawer. I originally designed it thinking I would have to use a pin to keep the plug in place but was able to make it a good snug fit was it stays with friction. There is a pin hole in the stem if someone wants to add a pin. The post that goes into the cabinet hole is 20 mm in diameter by 35 mm long, the cap is 45 mm wide.